Casting, Pressure Die

In pressure die casting, metal is melted and forced into steel dies. The metal hardens into the desired shape.

Molten metal is injected into a die cavity through a channel by movement of a plunger. After a preset solidification time, the plunger reverses direction, the part is ejected, and the machine is ready for the next cycle.

There are two types of die casting.

Hot chamber: This process involves the use of a plunger which traps a certain volume of molten metal and forces it into the die cavity through a gooseneck and nozzle. After the metal has solidified in the die cavity, the plunger is withdrawn, the die opens and the casting is ejected. Metals having low melting points such as Zinc, copper, magnesium and lead are cast using Hot chamber die casting.

Cold chamber: In this process molten metal is poured into the injection cylinder manually by a hand ladle or by an automatic ladle. The metal is forced into the die cavity at high pressures. High melting point alloys of aluminum and copper are normally cast using cold chamber die casting.

Possible shapes

A wide variety of complex 3D shapes.

Casting, Pressure Die Design Guidelines

• Keep wall thickness uniform and 0.1" to 0.5".

• Avoid complex shapes

• Avoid sharp internal corners

• Use ribs or fins to reduce distortion

• See Injection Molding guidelines for additional tips

• Include draft angles at sides to allow ejection

Example parts

Engine blocks, bushings, flywheels, levers, gears, automotive, aerospace, medical, appliances, toys and many more.

Advantages of Casting, Pressure Die

Parts without any joints can be made eliminating other processes such as welding and fastening. Integral fastening elements such as bosses and studs can be included. Good dimensional accuracy and detail. No further machining required usually. Low cost. 

Notes

Parting line is the location where the two mold halves meet. Ejector pins are small cylinders that push the part out of the mold. Some flashing will occur at parting line. Coarse external threads on parts can be formed. Varying textures can be manufactured.

Processes: Turning Milling Laser Cutting Water Jet Cutting Wire EDM Tapping Bending Turret Punching Fine Blanking Blanking Steel Rule Die Cutting Drawing Injection Molding Extrusion Metal Casting Thermoforming Forging Springs Wire forming Powder Coating